Diglycidylimidazolidones

ABSTRACT

DIGLYCIDYLHEXAHYDROBENZIMIDAZOLONE AND DIGLYCIDYLTETRAHYDROBENZIMIDAZOLONE. THESE COMPOUNDS CAN BE USED BY CURING WITH AMINES OR ANHYDRIDES, TO MANUFACTURE CASTING RESINS, ELECTRICAL RESINS, SINERING POWDERS AND OMPRESSION MOULDING COMPOSITIONS.

United' States Patent 3,828,066 DIGLYCIDYLIMIDAZOLIDONES Daniel Porret,Binningen, Switzerland, assignor to Ciba- Geigy Corporation, Ardsley,N.Y. No Drawing. Filed Dec. 29, 1972, Ser. No. 319,961 Claims priority,application/Savitzerland, Jan. 5, 1972,

Int. Cl. C07d 49/30, 49/34 US. Cl. 260-309.6 2 Claims ABSTRACT OF THEDISCLOSURE Diglycidylhexahydrobenzimidazolone anddiglycidyltetrahydrobenzimidazolone. These compounds can be used bycuring with amines or anhydrides, to manufacture casting resins,electrical resins, sintering powders and compression mouldingcompositions.

the cured resins.

The diglycidylhexahydrobenzimidazolidones according to the invention, ofthe formula and diglycidyltetrahydrobenzimidazolidones according to theinvention, of the formula wherein X denotes hydrogen or an alkyl groupwith 1 to 4 carbon atoms, especially the methyl or ethyl group, can bemanufactured easily and in good purity and lead to cured products whichare more stable to water than the known product.

The diglycidyl-others of the formula (I) and (II) can be manufacturedfrom the corresponding hexahydrobenzimidazolidones andtetrahydrobenzimidazolidones which possess, on the nitrogen atoms,groups which can be converted into epoxy groups, such as, in particular,a hydroxyhalogenopropyl group, for example the hydroxychloroethyl orhydroxybromoethyl group. The hydroxyl group can be in the 2- or3-position and the halogen can be in the 3- or 2-position. The reactionis carried out in the customary manner, above all in the presence ofagents which split off hydrogen halide, such as strong alkalis, forexample anhydrous sodium hydroxide or aqueous sodium hydroxide solution.However, other strongly alkaline reagents, such as potassium hydroxide,barium hydroxide, calcium hydroxide, sodium carbonate or potassiumcarbonate can also be used for the purpose.

A further radical which can be converted into the 1, epoxyethyl radicalis, for example, the prop-2-enyl group which can be converted into the2,3-epoxypropyl group in a known manner, such as, above all, by reactionwith hydrogen peroxide and a nitrile or with per-acids, for exampleperacetic acid, perbenzoic acid or monoperphthalic acid. The startingproducts can be obtained, for example, by reaction of 1 mol ofhexahydrobenzimidazoles or tetrahydrobenzirnidazoles with 2 mols of anepihalogenohydrin, above all epichlorohydrin, in the presence of acatalyst, such as, in particular, a tertiary amine, a quaternaryammonium base or a quaternary ammonium salt. Suitable catalysts for theaddition of epichlorohydrin are above all tertiary amines, such astriethylamine, tri n propylamine, benzyldimethylamine, N,Ndimethylaniline and triethanolamine; quaternary ammonium bases, such asbenzyltrimethylammonium hydroxide; quaternary ammonium salts, such astetramethylammonium chloride, tetraethylammonium chloride,benzyltrimethylammonium achloride, benzyltrimethylammonium acetate andmethyltriethylammoniup chloride; hydrazines with a tertiary nitrogenatom, such as 1,1 dimethylhydrazine, which can also be employed in thequaternised form; alkali halides, such as lithium chloride, potassiumchloride or sodium chloride, bromide or fluoride; further, ion exchangeresins with tertiary or quaternary amino groups and also ion exchangerswith acid amide groups. It is also possible to work without a catalyst.

The addition of the epihalogenohydrin to the hexahydrobenzimidazolidoneor tetrahydrobenzimidazolidone can be carried out with or withoutsolvent, with an excess of epichlorohydrin, at temperatures of up to 140C., under the action of one of the catalysts mentioned, over the courseof 30 to 360 minutes. The subsequent dehydrohalogenation can be carriedout at 40 to 70 C. with solid or liquid alkalis and optionally whilstazeotropically distilling off'the water formed. The alkali halide isseparated off in a known manner. The resulting diglycidyl derivativesare isolated by distilling off the excess epihalogenohydrin and, ifappropriate, the solvent. They are as a rule obtained as viscous,colourless to light brown liquids in yields of up toTetrahydrobenzimidazolidone is easily obtainable by reaction ofo-chlorocyclohexanone with urea. Catalytic hydrogenation oftetrahydrobenzimidazolidone with hydrogen yieldshexahydrobenzimidazolidone (trans-form).

The diglycidyl compounds according to the invention of the formulae (I)and (II) react with the customary curing agents for epoxide compounds.They can therefore be crosslinked or cured by addition of such curingagents, analogously to other polyfunctional epoxide compounds. Basic oracid compounds can be used as such curing agents.

As suitable curing agents there may, for example, be mentioned: aminesor amides, such as aliphatic, cycloaliphatic or aromatic, primary,secondary and tertiary amines, for example monoethanolamine,ethylenediamine, hexamethylenediamine, trimethylhexamethylenediamine,diethylenetriamine, triethylenetetramine, tetraethylenepentamine, N,Ndimethylpropylenediamine-1,3, N,N-diethylpropylenediamine 1,3, 2,2bis-(4'-aminocyclohexyl)propane, 3,5,5 trimethyl 3(aminomethyl)cyclohexylamine (isophoronediamine), Mannich bases, such as2,4,6 tris (dimethylaminomethyl)-phenol; mphenylenediamine,p-phenylenediamine, bis (4 aminophenyl)-methane,bis-(4-aminophenyl)-sulphone and mxylylenediamine; adducts ofacrylonitrile or monoepoxides, such as ethylene oxide or propyleneoxide, to polyalkylenepolyamines, such as diethylenetriamine ortriethylenetetramine; adducts of polyamines, such as diethylenetriamineor triethylenetetramine in excess, and polyepoxides, such asdiomethane-polyglycidyl-ethers; ketimines, for example from acetone ormethyl ethyl ketone and bis(p-aminophenyl)-rnethane; adducts ofmonophenols or polyphenols and polyamines; polyamides, especially thosefrom aliphatic polyamines, such as diethylenetriamine or triethylenetetramine, and dimerised or trimerised unsaturated fatty acids, such asdimerised linseed oil fatty acid (Versamid); polymeric polysulphides(Thiokol); dicyandiamide, aniline-formaldehyde resins; polyhydricphenols, for example resorcinol, 2,2-bis-(4- hydroxyphenylypropane orphenol-formaldehyde resins; boron trifluoride and its complexes withorganic compounds, such as Br -ether complexes and BF -amine complexes,for example B-F -monoethylamine complex; acetoacetanilide-B=F complex;phosphoric acid; triphenylphosphite; polybasic carboxylic acids andtheir anhydrides, for example phthalic anhydride, A -tetrahydrophthalicanhydride, hexahydrophthalic anhydride, 4 methylhexahydrophthalicanhydride, 3,6 endomethylene A tetrahydrophthalic anhydride, 4methyl-3,-6-endomethylene- A tetrahydrophthalic anhydride (=methylnadicanhydride), 3,4,5,6,7,7 hexachloro 3,6 endomethylene-Atetrahydrophthalic anhydride, succinic anhydride, adipic anhydride,trimethyladipic anhydride, azelaic anhydride, sebacic anhydride, maleicanhydride, dodecenyl-succinic anhydride; pyromellitic dianhydride ormixtures of such anhydrides.

Curing accelerators can furthermore be employed in the curing reaction,and in particular when using polyamides, dicyandiamide, polymericpolysulphides or polycarboxylic acid anhydrides as curing agents; suchaccelerators are, for example, tertiary amines, their salts orquaternary ammonium compounds, for example 2,4,6-tris-(dirnethylaminomethyl) phenol, henzyldimethylamine, 2 ethyl-4-methyl-imidazole and triamylammonium phenolate; or alkali metalalcoholates, such as, for example, sodium hexanetriolate.

A further subject of the invention are curable mixtures which contain adiglycidyl compound according to the invention, of the formula (I) or(II), optionally together with other polyepoxide compounds, and alsocuring agents for epoxide resins, such as polyamines or polycarboxylicacid anhydrides.

The diglycidyl compounds according to the invention or their mixtureswith other polyepoxide compounds and/ or curing agents can be mixed,before curing, with customary modifiers, such as extenders, fillers andreinforcing agents, pigments, dyestuffs, plasticisers, flow controlagents, agents for conferring thixotropy, flameproofing substances andmould release agents.

As extenders, reinforcing agents, fillers and pigments which can beintroduced into the curable mixtures according to the invention theremay, for example, be mentioned: coal tar, bitumen, glass fibres, boronfibres, carbon fibres, cellulose, polyethylene powder, polypropylenepowder, mica, asbestos, quartz powder, slate powder, aluminium oxidetrihydrate, chalk powder, gypsum, antimony trioxide, bentones, silicaaerogel (Aerosil), lithopone, bary-te, titanium dioxide, carbon black,graphite, iron oxide or metal powders, such as aluminium powder or ironpowder. Suitable organic solvents for modifying the curable mixturesare, for example, toluene, xylene, n-propanol, butyl acetate, acetone,methyl ethyl ketone, diacetone alcohol, ethylene glycol monomethylether,monoethyl ether and monobutyl ether.

Particularly for use in the lacquer field, the new diglycidyl compoundscan furthermore be partially or completely esterified in a known mannerwith carboxylic acids such as, in particular, higher unsaturated fattyacids. It is furthermore possible to add other curable synthetic resins,for example phenoplasts or aminoplasts, to such lacquer resinformulations.

The curable mixture can serve, in the unfilled or filled state,optionally in the form of a solutions or emulsions, as laminatingresins, paints, lacquers, dipping resins, impregnating resins, castingresins, compression moulding compositions, sintering powders, spreadingand surface- -filiing compositions, floor covering compositions, pottingand insulating compositions for the electrical industry, and adhesives,and for the manufacture of such products.

Cured mouldings of this resin display good heat stability, goodelectrical properties and outstanding stability to water, coupled withgood mechanical properties.

MANUFACTURING EXAMPLES Example 1 56 g. of hexahydrobenzimidazolidone(0.4 mol) together with 740 g. of epichlorohydrin (8.0 mols) and 0.5 g.of tetramethylamrnonium chloride are stirred for minutes at 118 C.Hereupon, a clear dark solution results. An azeotropic circulatorydistillation is established by application of vacuum ('6090 mm. Hg) atan external temperature of l40l48 C. in such a Way that at a temperatureof the reaction mixture of 5961 C. a vigorous distillation takes place.70.4 g. of 50% strength aqueous sodium hydroxide solution are then addeddropwise over the course of 5 hours whilst stirring vigorously; at thesame time the water present in the reaction mixture is continuouslyremoved azeotropically, and separated ofi.

Thereafter, distillation is carried out for a further 60 minutes underthe conditions indicated in order to remove the last remnants of waterfrom the batch. The batch is then cooled to about 35 C. The sodiumchloride produced in the reaction is removed by filtration; the residueis washed with a little epichlorohydrin and the combined epichlorohydrinsolutions are extracted by shaking with 400 ml. of water, to remove saltand remnants of alkali. The organic phase is concentrated at 60 C. undera water pump vacuum and is then dried to constant weight at 100 C./0.2mm. Hg 89 g. (88.2% of theory) of a liquid, light brown resin with 6.73epoxide equivalents/ kg. (84.8% of theory), essentially corresponding tothe following structure Analogously to Example 1, 420.5 g. oftetrahydrobenzimidazolidone (3.0 mols) are treated with 2.5 g. oftetramethylarnmonium chloride in 4,700 ml. of epichlorohydrin (60.0mols). The dehydrohalogenation is again carried out according to Example1, with 528 g. of 50% strength aqueous sodium hydroxide solution (6.6rnols). The working up and isolation of the product is carried out inthe usual manner. 747 g. (99.5% of theory) of a clear, light brown,viscous liquid containing 0.65% of total chlorine and having an epoxidecontent of 7.50 equivalents/kg. (93.6% of theory) are obtained.

The product can be purified as follows:

It is first subjected to a high vacuum distillation; this yields aproduct with 7.90 epoxide equivalents per kilogram which boils at -162"C./ 0.08 mm. Hg and slowly crystallises at room temperature. Thissubstance is recrystallised in the ratio of 1:4 from a mixture ofacetone/ ether (1:5). Colourless crystals are obtained, which melt at88-91 C. and have an epoxide content of 7.98 epoxide equivalents/kg.(99.9% of theory).

The microanalysis gives the following values: Calculated (percent): C,62.38; H, 7.25; N, 11.10. Found (percent): C, 62.48; H, 7.28; N, 11.26.

Accordingly, the new diglycidyl compound corresponds to the followingstructure:

HH HH Example 3 Analogously to Example 1, 6.9 g. ofS-methyl-tetrahydrobenzimidazolidone (0.0453 mol) are reacted with 0.3g. of tetramethylarnmonium chloride in 125.6 g. of epichlorohydrin(1.358 mols) at 115118 C. The dehydrohalogenation is also carried outaccording to Ex ample 1 with 7.98 g. of 50% strength aqueous sodiumhydroxide solution (0.0996 mol). After the customary working up of theproduct, 11.9 g. (100% of theory) of a viscous, light brown resin with6.93 epoxide equivalents/kg. (91.7% of theory), essentiallycorresponding to the following structure:

H H H CH H H O H H O are obtained.

USE EXAMPLES Example I 100 g. of the crude epoxide resin obtainedaccording to Example 2, containing 7.50 epoxide equivalents/kg, aremixed with 106 g. of hexahydrophthalic anhydride at 80 C. to give ahomogeneous melt and the mixture is deaerated and poured into analuminium casting mould prewarmed to 80 C. Curing takes place in 5 hoursat 80 C.+2 hours at 120 C.+ hours at 150 C. Clear, transparent mouldingshaving the following excellent mechanical properties are obtained:

Flexural strength (VSM) kp./m. 1418.5 Deflection (VSM) mm 4.5-7.3 Impactstrength (VSM) cm.-kp./cm. 16-20 Heat distortion point according toMartens (DIN) C-.. 154 Water absorption (1 hour at 100 C.) percent..0.58

Example H 100 parts by weight of the epoxide resin manufacturedaccording to Example 2 are mixed with 37 parts by weight ofmethylenebisaniline and cured for 2 hours at 80 C. and 8 hours at 140C., as indicated in Example I. The mouldings show the followingproperties:

parts by weight of the epoxide resin manufactured according to Example 2are cured with 44 parts by weight of4,4'-diamino-3,3'-(dimethyldicyclohexyl)-methane for 24 hours at 40 C.and 6 hours at 100 C. The mouldings obtained as in Example I show thefollowing properties: 'Impact strength (VSM) cm.-kp./cm. 12.6 Flexuralstrength (VSM) kp./mm. 14.3 Deflection (VSM) mm 4.6 Heat distortionpoint according to Martens (DIN) C-.. 119 Water absorption (1 hour inboiling water) percent 0.77 Tensile shear strength on Anticorodal Bkg./mm. 0.6

What is claimed is: 1. A diglycidyl compound of Formula (I) or (II) inwhich X denotes hydrogen or alkyl of 1 to 4 carbon atoms.

2. A diglycidyl compound according to claim 1, whereing X in formula (I)or (II) denotes methyl or ethyl.

References Cited UNITED STATES PATENTS 3,429,833 2/1969 Porret 260-309]FOREIGN PATENTS 1,932,306 3/1970 Germany 260-309.7

NATALIE TROUSOF, Primary Examiner U.S. Cl. X.R.

260-2 EC, 2 EA, 2 EP, 18 EP, 30.4 EP, 30.6 R, 31.8 37 EP, 78.4 EP,309.7, 824 EP, 830 R, 830 TW, 830 831, 834, 835, 836

